Miniature robots on the millimeter scale often lack the strength to transport instruments for endoscopic microsurgery through the body. Scientists at the German Cancer Research Center (DKFZ) are now combining several millimeter-sized TrainBots into one unit and equipping them with improved �feet�. For the first time, the DKFZ team was able to perform an electric surgical procedure on a bile duct obstruction experimentally with a robotic convoy.